Process for magnetic separation of emulsions



Oct. 30, 1934. c. |-i. M.VROBERTS 1,978,509

PROCESS FOR MAGNETIC SEPARATION OF EMULSIONS Original Filed May 15, 1929 04/. M ROEERTJ.

QTTORA/E J Patented Oct. 30, 1934- raocass roa MAGNETIC scram-non or EMULSIONS Claudius n. M. Roberts, Long Beach, Calif., as

signor, by means assignments, to Petroleum Calif., a corporation of California Bectifying Company of California, Los Angeles, I

Application May is, 1929, Serial No. 303,198

- Renewed February 4, 1933 scum. (1204-24) This invention relates to the separation of emulsions by the action of magnetism, and particularly, to the magnetic treatment of petroleum emulsions of the water-in-oil type, so as to effect the separation of the component parts of such emulsions; and to apparatus therefor.

My invention resides in the application of a magnetic field to an emulsion system, for the purpose of separating it into its component phases. The magnetic field applied is preferably alternating in character, altho it may also be uni-directional or consist of super-imposed alternating and uni-directional fields, and, when alternating, may be of any frequency suitable for the purpose. The purpose of this invention is to effect the separation of emulsions by the action of magnetic fields, in the absence of separately produced or maintained electric fields.

I have discovered that magnetic fields may be utilized for the resolution of emulsions and that their effects are entirely analogous to the effects of electric fields upor femulsions. I have found that, whereas some emulsions can be successful- 1y resolved by the action of uni-directional magnetic fields and of alternating magnetic fields of commercial frequencies, analogous to uni-directionals-affid commercial frequency alternating electric fields, there are many emulsions which can only be successfully resolved by magnetic fields of suitable special frequencies, analogous to the special frequency alternating electric fields covered by my co-pending application No. 340,855, filed February 18, 1929. For emulsions which cannot, be efliciently resolved by uni-directional oncommercial frequency alternating magnetic fields, the specific frequency best suited for the. particular emulsion may-be determined by determining (1) the range ofi'equencies within which treatment is possible at the lowest magnetic field intensities-which I will refer to as the critical frequency range, and (2) that particular frequency, within this critical frequency range, which enables the use of the minimum magnetic field intensity, which frequency I will refer to as the optimum frequency.

1 have also found that, in certain cases, it is desirable to employ magnetic fields which are compound in character, that is, they consist of both uni-directional and alternating fields, which are superimposed upon the emulsion to be separated. Such magnetic fields may be produced from separate sources of magnetic energy, as by the use of double magnets suitably energized by direct and alternating current sources, respectively, or by the use of a single magnet which is energimd-by a single source of electricity, whose current wave contains both alternating and unidirectional components. The efi'ect of employing such compound, or superimposed uni-directional and alternating, magnetic fields is, in certain 00 cases, depending upon the characteristics of the particular emulsion, to enable its successful separation at a magnetic field intensity lower than would be practicable with an alternating field alone. The frequency of the alternating com- 66 ponent of the field should be so chosen as to lie within the critical frequency range for the given emulsion and should preferably be the optimum frequency for that emulsion, this frequency having previously been determined for various values 70 of field intensity for the uni-directional coinponent.

Among the advantages which are immediately apparent from a consideration of the process herein disclosed, attention should be directed to the absence of applied electric potentials, such as are employed in electrical processes for separation of emulsions. By eliminating the necessity for high electric potentials, thedanger of accidents due to electric shocks to persons, aswell as the possibility of fires or explosions, due to lgnition of inflammable materials by electric discharges, are entirely eliminated. In addition, since there is no externally applied electric field used in connection with my process, the difilculties and embarrassments attendant upon the disruptive passage of current through the emulsion, which have formed the subject of numerous patents directed to electrical resolution of emulsions, are also entirely eliminated,

A further advantage of the process here dis-' closed is that it can be used equally as efliciently, and without special arrangements for prevention of short circuits, such as are necessary in electrical processes, for the resolution of ofl-in-water emulsions, as for water-in-oil emulsions.

Still another advantage of my process lies in the heat induced in the emulsion by the inductive action of the magnetic field. In this respect, the process is similar to heating by magnetic induction, and the amount of heat induced in the emulsion during treatment is usually sufilcient to obviate the necessity of supplying heat from other sources, except in the case of very viscous emulsions or where a relatively high temperature must be employed. The character of the inductive heating produced by the magnetic field is especially favorable for emulsions as, unlike other usually employed heating systems, it does not tend to cause the partial evaporation of the particles of the dispersed phase andtheir condensation as smaller particles.

From the'foregoing, it will be seen that I have made a discovery that is of great value to industry and which consists of the fact that emulsions can be separated by the action of magnetic fields, without the direct application of electricity to the emulsion, and also that lower magnetic field intensities may be employed successfully, provided the magnetic field has a suitable frequency or consists of a suitable combination of uni-directional and alternating magnetic fields, the alternating component of which has a suitable frequency. From this discovery I have been able to devise a magnetic process by which many emulsions can be separated easily, quickly and economically and ate minimum magnetic field intensity.

In the practice of my process, I may prefer to employ, as the source of the magnetic field, an electromagnet, of essentially horse-shoe form, with large pole pieces, which are separated by a gap, the length of which is small as compared to its cross-sectional area; the gap being occupied by a conduit, preferably constructed of essentially non-magnetic and non-metallic materials, such as glass or bakelite, through which the emulsion is permitted to fiow during subjection to the magnetic field. Or I may prefer to employ, as the source of the magnetic field, an electromagnet,

which may be of any shape and whose core consists of a conduit, preferably constructed of essentially non-magnetic and non-metallic materials, such as glass or bakelite, through which the emulsion is permitted toflow during subjection to the magnetic field. The magnet is energized by an electric current of such characteristics as will produce a magnetic field of suitable kind, as previously described, and of suitable intensity for the emulsion to be separated, which current, at a potential suited to the characteristics of the electromagnet, may be produced by any suitable means, such as a generator, battery, vacuum tube frequency generator, vacuum tube rectifier, etc. The energizing current may be uni-directional, alternating, or compound (1. e., contain both unidirectional and alternating components) and the frequency may have any value suitable for the purpose. The magnet is of such construction and characteristics as will enable the generation of a magnetic field of suitable characteristics, when energized by the current provided.

Various types and kinds of apparatus may be used to practice or carry out my process. The accompanying drawing illustrates one suitable form of apparatus, which is provided with a generator that constitutes the source of electrical energy. In the said drawing, 1 and 2 designate the commercial electric supply mains from which the operating power is drawn, 3 designates the line switch, connected by wires 4 and 5 to a motor 6, of characteristics suited to the commercial power available, 7 designates a frequency generator, which may produce a voltage of sinusoidal or other desirable wave form, and 8 designates a direct current generator; said frequency generator '7 and direct current generator 8 being mounted on the same shaft as the motor 6.

erator 8 supplies current, for excitation, to the field coils 9, of the frequency generator 7, being suitably connected thereto by wires 9a. The frequency generator 7 is connected by wires 10 and 11, with switch 12 and thence, through wires 13 and 14, to one coil 15, of a suitable transformer 21, or type suited to the frequency to be used.

The gen-,

Suitably connected in the circuit from the frequency generator 7 are a circuit breaker 16, a current limiting or regulating device 17, an ammeter 18, a voltmeter 19, a frequency meter 20, and, when desired, a commutating device indicated by 20a, which may be employed for the purpose of enabling the use of only such part of the voltage wave as may be desired, all substantially as shown in the drawing. The other coil 22, of the transformer 21, is connected by wires 23 and 24, respectively, to the terminals of the coil 26, which forms a part of the magnetic treater 27. The treater 27 consists, in addition to the energizing winding 26, of a substantially axial conduit 25, preferably constructed of non-magnetic, non-metallic material, through which the emulsion to be separated is permitted to pass and in which it is subjected to the action of the magnetic field. The emulsion is delivered to the treater through pipe 28, substantially as shown,

whence it fiows through conduit 25 and is removed from the treater through pipe 29, being delivered, if desired, into the bottom of a settling tank 30, of well known design, within which the component phases of the emulsion are permitted to separate by gravity and from which the separated liquids may be withdrawn through pipes 31 and 32, respectively.

In practicing my process, the emulsion to be separated is permitted to flow continuously, and at a suitable rate, through pipe 28 and thence through the treater, through conduit 25. The switch 3, on the power supply lines 1 and 2, is then closed, thereby starting the motor 6 and the generators 7 and 8, mechanically connected thereto. The speed of motor 6 is then regulated, by apparatus not shown, until the frequency meter 20, in the output circuit of generator 7, indicates the desired frequency and the current in the field coils 9, of the generator 7, is adjusted, by regulating the output of generator 8, by apparatus not shown, until the desired output voltage of generator 7 is indicated by voltmeter 19. The circuit breaker 16 and the switch 12 are then closed, thereby energizing transformer 21, the output voltage of which, at the generated frequency, is delivered through wires 23 and 24 to the coil 26, of the treater 27, thereby energizing coil 26 and setting up a magnetic field, of suitable intensity at the generated frequency, in the conduit 25. The magnetic field in conduit 25, being impressed upon the emulsion flowing therethrough, causes the coalescence of the droplets of the dispersed phase. The coalesced liquids then flow out of 'the treater through pipe 29 and into settling tank 30, in which they are permitted to separate by gravity into continuous phases and from which they are withdrawn, as desired, through pipes 31 and 32, respectively.

In treating certain emulsions, which, due to various causes, may be more or less resistant to the action of magnetism, or in treating mixed emulsions, such as "tank bottoms and mixtures of fresh emulsions, it is sometimes necessary to subject the emulsion to repeated action of the magnetic field, either at the same or at different frequencies and at the same or at different field intensities. Such repeated action of the magnetic field may be secured in the same or in different apparatus, as may be most suitable under the circumstances. In the event that different frequencies are required, those frequencies are determined, as previously described, for each component of the mixed emulsion.

In the foregoing description of my process, it 15 ponents.

is to be distinctly understood that I do not limit myself in any manner to the method or apparatus herein disclosed for practicing my process: the only essential featureof the process being the subjection of an emulsion to be separatedto the-action of a magnetic field, which field may be of any suitable frequency and any suitable intensity for the purpose. The magnetic field may be uni-directional, alternating, or may contain both uni-directional and alternating com- The alternating field, or alternating component of a field containing both uni-directional and alternating components, may have any suitable frequency, such frequency preferably being the optimum frequency for the given emulsion. The magnetic field may be produced and maintained in any manner and the emulsion, which may consist of any two or more non-miscible liquids, may be subjected to the action of this magnetic field in any suitable apparatus, the

component liquids being separated into continuous phases either within said apparatus or, subsequently, in any other suitable apparatus. It is obvious that this process is applicable to all types and forms of emulsions, irrespective of whether the outer, or continuous, phase is or is not a conductor of electricity. While my process is particularly adapted for breaking or separating petroleum emulsions of the water-in-oil type, it

is not limited to such use, but is capable of use artificial emulsions.

If desired, my improved process may be used in conjunction with certainauxiliary processes, apparatus, or procedure used in the treatment of petroleum emulsions, such, for example, as processes, apparatus, or procedure which efiect or have for their purpose; homogenization of the emulsion with steam or by mechanical means; re-emulsification with added water or brine; reduction of water content by addition and suitable incorporation of un-emulsified oil of the same or different characteristics from the oil in the emulsion; addition and incorporation with the emulsion of lighter oil, in order to reduce the viscosity of the emulsion; the use of heat or pressure or both to facilitate the action of the magnetic treatment; the use of agitation produced by any means, before, during or subsequent to the magnetic treatment; the repeated subjection of the emulsion to the magnetic action, either in the same or different apparatus and at the same or different field intensity from that first employed; the subjection of the emulsion to magnetic action in a field of varying magnetic field intensity, which may vary continuously or periodically between any desirable limits or which may be varied' manually as desired; the use of filtration either within or outside the treater, as an aid to the magnetic action; the use of centrifugal force either during or subsequent to the magnetic action; the use of a moving magnetic field, controlled by any means, to'facilitate the treatment; mixing treated or partially treated emulsion with other emulsion prior to treatment or recycling the same through the treater to subject it to repeated action of the magnetic field; control of fiuid level or water level in the treater or the use of fluid level or water level in the treater to control other apparatus, such as power supplied to energize the magnetic field, or water or fluid withdrawn from the treater; insulation,

protection of the electrically energized elements of the treater, such as, of the energizing windings of the magnets, or of any auxiliary apparatus; the use of magnetic fields or of a treater of particular or specially desirable design; the separation of the component phases of the emulsion, either partially or completely, prior to, during or subsequent to-the magnetic action, either in the treater or in auxiliary apparatus of any form; or addition to the emulsion to be separated of any suitable chemicals, added either prior to or during the magnetic'treatment, for the purpose'of altering any physical or chemical properties of the components of the system, such as conductivity, surface tension, dielectric constant, solubility, magnetic susceptibility, viscosity, etc., so as to render the emulsion more susceptible to magnetic separation.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A process for separating a mixed emulsion, which comprises subjecting the emulsion to repeated action of magnetism at different frequencies, each of which frequencies is adapted for one component of the mixture.

2. A process of treating emulsions, which includes the steps of setting up a magnetic field which is of predetermined critical frequency and magnitude to coalesce the dispersed droplets in the emulsion to be treated; introducing a raw emulsion into one portion of said magnetic field whereby said magnetic field coalesces the dispersed droplets of said raw emulsion into larger masses; removing the magnetically treated emulsion from another portion of said field; and separating the coalesced masses from the remainder of the constituents of said emulsion.

3. A process of treating emulsions to separate the constituents thereof, which method includes the steps of subjecting to the actionof a magnetic field which is of predetermined critical frequency and magnitude to coalesce the dispersed droplets in the emulsion to be treated; a raw emulsion containing dispersed droplets too small to quickly gravitate from the continuous phase of said emulsion whereby said magnetic field coalesces said droplets into larger masses; varying the intensity of said magnetic field during the time said emulsion is subjected to the action thereof; and subsequently separating said larger masses from said continuous phase.

4. A process of treating emulsions to separatethe constituents thereof, which method includes the steps of: flowing a stream of raw emulsion through a pipe; sending a magnetic flux through the walls of said p pe to treat said raw emulsion to agglomerate the dispersed droplets thereof,

said "magnetic fiux being formed by a potential of predetermined critical frequency and magnitude to coalesce the dispersed droplets in said emulsion; removing the treated emulsion from said pipe; and separating said constituents of said treated emulsion.

5. A process of treating emulsions to separate the constituents thereof, which method includes the steps of: flowing astream of raw emulsion through a pipe; sending a magnetic flux through of, said magnetic flux being formed by a potential I of predetermined critical frequency and magnitude to coalesce the dispersed droplets in said emulsion; removing the treated emulsion from said pipe; and separating said constituents of said treated emulsion.

6.' A process of treating emulsions to separate the constituents thereof, which process includes the steps of: setting up a magnetic field by the use or an electric current; subjecting saidemulsion while in a raw state tothe action of said magnetic field whereby the dispersed droplets of said emulsion are coalesced into larger masses; periodically interrupting said electric current during the time said emulsion is undergoing treatment; and subsequently separating said coalesced masses from the remaining constituents of said emulsion.

7. 'A process or treating emulsions to separate the constituents thereof, which process includes the steps of: setting up a unidirectional pulsating magnetic field; setting up a magnetic fleld 01' alternating character; and subjecting the emulsion to be treated to the action or each of said fields.

8. A process of treating emulsions to separate the constituents-thereof, which process includes the steps of: establishing a magnetic fleldot compound character and including superimposed unidirectional and alternating magnetic field components; subjecting the emulsion to be treated to the action of said magnetic field of compound character to coalesce the dispersed droplets forming the dispersedphase of said emulsion; and separating said coalesced droplets from the remainder of said emulsion.

. CLAUDIUS H. M. ROBERTS.

CERTIFICATE OF CORRECTION.

Patent No. l, 978, 509.

October 30, 1934.

CLAUDIUS H. M. ROBERTS.

It is hereby certified that error appears in the printed specification of-the above numbered palent requiring correction as follower Page 3 line 116, .after "treated" strike out-the semi-colon; and that the saidLetters Patent should be read with this correction therein that the same case in the Patent Office.

Signed and sealed this 8th day of January, A. D. 12115.

s 1 ie Frazer Act .Coumissioaer of Pa tents.

may conform to the record of the 6.' A process of treating emulsions to separate the constituents thereof, which process includes the steps of: setting up a magnetic field by the use or an electric current; subjecting saidemulsion while in a raw state tothe action of said magnetic field whereby the dispersed droplets of said emulsion are coalesced into larger masses; periodically interrupting said electric current during the time said emulsion is undergoing treatment; and subsequently separating said coalesced masses from the remaining constituents of said emulsion.

7. 'A process or treating emulsions to separate the constituents thereof, which process includes the steps of: setting up a unidirectional pulsating magnetic field; setting up a magnetic fleld 01' alternating character; and subjecting the emulsion to be treated to the action or each of said fields.

8. A process of treating emulsions to separate the constituents-thereof, which process includes the steps of: establishing a magnetic fleldot compound character and including superimposed unidirectional and alternating magnetic field components; subjecting the emulsion to be treated to the action of said magnetic field of compound character to coalesce the dispersed droplets forming the dispersedphase of said emulsion; and separating said coalesced droplets from the remainder of said emulsion.

. CLAUDIUS H. M. ROBERTS.

CERTIFICATE OF CORRECTION.

Patent No. l, 978, 509.

October 30, 1934.

CLAUDIUS H. M. ROBERTS.

It is hereby certified that error appears in the printed specification of-the above numbered palent requiring correction as follower Page 3 line 116, .after "treated" strike out-the semi-colon; and that the saidLetters Patent should be read with this correction therein that the same case in the Patent Office.

Signed and sealed this 8th day of January, A. D. 12115.

s 1 ie Frazer Act .Coumissioaer of Pa tents.

may conform to the record of the 

